From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 285DD1EF38F for ; Fri, 28 Feb 2025 15:32:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740756759; cv=none; b=en4KRDEBSi2kARU8fgZhvDZvg46+Tewt36gdG8ZfjRQie9sFg1QGEPG08OS7txu7AsnSMIsDcLNnGvM4BN/0sCZ2Ha0ErhvEpEgbjuDni6SQXfWTlMDXOj3mxtBKxlNSFfYNOHwUz99Y60++L9dgwPSvE3kvz7vjdpZL1auqkC0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740756759; c=relaxed/simple; bh=qVmyXvzIJJsl8HgB675jC4uABINWt4XEGa0kFziWnhw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=jDtx8NKypvAR2k6j57/n92WcrroHBzznCa3eCw+MF2cmG0dV2QZBduN/uO5kwofcBakKrb/PRDk4kE/pWaWYvryjhaGHfvyRGhO/OfP+Jo/gISjRkoxe92X3PTehC6r+rUi8fDullvgd5R+6EjcsaMEM8nGx3OWQrqcFGOjIRm4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 908311515; Fri, 28 Feb 2025 07:32:52 -0800 (PST) Received: from [10.57.85.134] (unknown [10.57.85.134]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7E1173F5A1; Fri, 28 Feb 2025 07:32:35 -0800 (PST) Message-ID: Date: Fri, 28 Feb 2025 15:32:33 +0000 Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH V2 0/8] arm64/mm: Drop PXD_TABLE_BIT Content-Language: en-GB To: Anshuman Khandual , arm-kernel@lists.infradead.org Cc: Marc Zyngier , Oliver Upton , James Morse , Catalin Marinas , Will Deacon , Ard Biesheuvel , Mark Rutland , kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20250221044227.1145393-1-anshuman.khandual@arm.com> From: Ryan Roberts In-Reply-To: <20250221044227.1145393-1-anshuman.khandual@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 21/02/2025 04:42, Anshuman Khandual wrote: > Remove the PXX_TABLE_BIT definitions and instead rely on PXX_TYPE_MASK, > PXX_TYPE_SECT and PXX_TYPE_TABLE. The latter versions are more abstract > and also include the PTE_VALID bit. > > This abstraction is valuable for the impending D128 page table support, > which doesn't have a single page table bit to determine table vs block. > Instead it has the skip level (SKL) field, where it will consider 0 to > mean table and any other value to mean a block entry. So PXX_TABLE_BIT > therefore doesn't fit into the D128 model well, but the type fields do. All the patches look logically correct to me and I agree with the intention of removing PXX_TABLE_BIT. But personally I'd prefer to see a single patch that just does everything that's required to remove PXX_TABLE_BIT. And then a second patch for the pud_bad() fix/improvement (currently patch 6) which is orthogonal to the removal of PXX_TABLE_BIT. That would make it much easier to review IMHO, and would also allow for writing a single commit log which provides the justification for the change. I find the current set of 7 commit logs to not be hugely helpful. But I wrote the original patches and wrote them as I'm suggesting, so I would say that :) I'm guessing I shouldn't provide a Reviewed-By here, given I wrote the code originally... Thanks, Ryan > > This series applies on v6.14-rc3. > > Changes in V2: > > - Changed pmd_mkhuge() and pud_mkhuge() implementation > - Changed pud_bad() implementation with an additional patch > > Changes in V1: > > https://lore.kernel.org/all/20241005123824.1366397-1-anshuman.khandual@arm.com/ > > Cc: Marc Zyngier > Cc: Oliver Upton > Cc: James Morse > Cc: Catalin Marinas > Cc: Will Deacon > Cc: Ard Biesheuvel > Cc: Ryan Roberts > Cc: Mark Rutland > Cc: kvmarm@lists.linux.dev > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-kernel@vger.kernel.org > > Anshuman Khandual (6): > KVM: arm64: ptdump: Test PMD_TYPE_MASK for block mapping > arm64/ptdump: Test PMD_TYPE_MASK for block mapping > arm64/mm: Clear PXX_TYPE_MASK in mk_[pmd|pud]_sect_prot() > arm64/mm: Clear PXX_TYPE_MASK and set PXD_TYPE_SECT in [pmd|pud]_mkhuge() > arm64/mm: Check PXD_TYPE_TABLE in [p4d|pgd]_bad() > arm64/mm: Drop PXD_TABLE_BIT > > Ryan Roberts (2): > arm64/mm: Check PUD_TYPE_TABLE in pud_bad() > arm64/mm: Check pmd_table() in pmd_trans_huge() > > arch/arm64/include/asm/pgtable-hwdef.h | 5 -- > arch/arm64/include/asm/pgtable.h | 65 ++++++++++++++++++-------- > arch/arm64/kvm/ptdump.c | 4 +- > arch/arm64/mm/ptdump.c | 4 +- > 4 files changed, 50 insertions(+), 28 deletions(-) >